Waterproof watch with improved seal construction

ABSTRACT

An improved seal construction for a waterproof watch consists of a glass annulus having a tubular portion thin enough to exhibit some flexibility, a flexible seal ring and a case body. The seal ring makes interference fit with both the tubular portion of the glass annulus and the case body.

United States Patent Fujimori- Y [451 l)ec.5, 1972 [541 WATERPROOF WATCH WITH IMPROVED SEAL CONSTRUCTION [72] Inventor: Yoshiaki Fuiimori, Suwa, Japan [73] Assignee: Kabushiki Kaisha, Suwa Seikasha,

Tokyo, Japan 22 Filed: April 22, 1971 [21 App]. No.: 136,428

[30] Foreign Application Priority Data April 24, 1970 Japan ..45/34750 April 24, 1970 Japan ..45/34751 April 24, 1970 Japan ..45/347 52 [52] US. Cl. ..58/90 R [51] Int. Cl. ..G04b 37/08 [58] Field of Search ..58/88 R, 90 R, 91

[56] References Cited UNITED STATES PATENTS 7 2,308,189 1/1943 Marti ..58/9l X Starke ..'.....58/91 X Bauer ..58/91 X FOREIGN PATENTS OR APPLICATIONS 328,498 3/1958 Switzerland 58/91 Primary Examiner-Richard B. Wilkinson Assistant ExaminerGeorge H. Miller, Jr. Attorney-Blum, Moscovitz, Friedman & Kaplan [5 7] ABSTRACT An improved seal construction for a waterproof watch consists of a glass annulus having a tubular portion thin enough to exhibit some flexibility, a flexible seal ring and a case body. The seal ring makes interference fit with both the tubular portion of the glass annulus and the case bodyl 9 Claims, 9 Drawing Figures PATENTEDnzc 5:912 3.704.584

SHEET 2 OF 3 Fla. 4

WATERPROOF WATCH WITH IMPROVED SEAL CONSTRUCTION 1 BACKGROUND OF THE INVENTION In conventional watches designed to be waterproof, it is conventional to use rubber rings as part of the seal assembly. Such an assembly may consist of a watch glass, a bezel, a case body, and the rubber sealing ring. Although such rings can be effective under relatively mild conditions, it is found that rubber flexible enough to permit assembly of the seal is subject to deformation at high pressures so that leakage may occur. Moreover, the rubber tends to harden with time so that the effectiveness of the seal may decrease.

Adhesives may be used to replace flexible packing, but in the-event of breakage of a watch glass it is extremely difficult to remove all of the glass fragments in preparation for replacement. In fact, if such a construction is used, it is generally necessary to replace the entire-case body as well as the watch glass, an expensive way to cope with the problem.

SUMMARY OF THE INVENTION In an improved seal construction for a waterproof watch, the watch glass is sealed to a glass annulus which, in general, is essentially cylindrical and which is thin enough to exhibit some flexibility. A seal ring which has some flexibility but which is stiffer than the conventional rubber ring used in waterproof watches engages the tubular portion of the glass annulus in an interference fit. The case body also has an annular periphery and this periphery is engaged by the seal ring in a second interference fit.

The advantage of the above construction over the conventional construction is that part of the flexibility necessary for making the interference-fit is supplied by the glass annulus, so that a stiffer seal ring can be used. As a consequence, the seal ring can withstand higher pressures than is ordinarily the case.

Suitable materials for the seal ring are plastic and soft metals.

Accordingly, it is an object of the present invention to provide an improved seal construction for waterproof watches wherein the maximum pressure at which the seal is reliable is increased over that of conventional seals.

Another object of the invention is to provide an improved seal construction wherein' replacement of a broken watch glass is more readily carried out.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises an article of manufacture possessing the features, properties, and

FIG. 2 is a cross section of an embodiment showing a method of increasing the flexibility of the glass cylinder;

FIG. 3 is a cross section showing a method of retaining the seal ring within the case body;

FIG. 4 is a cross section of an embodiment in which the case body makes contact with the seal ring along a ridge;

FIG. 5 is a cross section in which the glass annulus seats in an axial direction on the seal ring;

FIG. 6 is a cross section in which both the case body and the seal ring are undercut;

FIG. 7 is a cross section-in which both the case body and the glass annulus have grooves therein in which the seal ring seats;

FIG. 8 is a cross section in which the seal ring is L- shaped and seats on a shoulder of the case body; and

FIG. 9 is a cross section in which the glass cylinder is external to the seal ring and the case body periphery against which the seal ring seats.

DESCRIPTION-OF THE PREFERRED EMBODIMENTS In the seal construction embodiment of FIG. 1, a watch glass 11 is sealed to a glass annulus 12 in such a manner as to preclude leakage at the joint. If desired, the watch glass 11 and the annulus 12 could be in one piece, or alternatively, could be cemented together. The glass annulus 12 has a tubular portion 13 which is thin enough to be flexible in a radial direction but nevertheless is not so thin as to be fragile. The tubular portion 13 engages a seal ring 14 at a surface, I5 of the tubular portion. The seal ring 114 is of a flexible material harder than the conventional rubber seal ring used in waterproof watches. A suitable material is plastic or a soft metal such as copper or silver. The outer diameter of the portion 13 is somewhat larger than the inner diameter of the seal ring 14, resulting in an interference fit when the two parts are engaged. The seal ring 14 also engages a case body 16 at an inner surface 17, the diameter of the surface 17 being somewhat'less than the outer diameter of the seal ring 14 so that the seal ring and the case body engage each other in a second press-fit. It is to be noted that the combined flexibilities of the seal ring I4 and the tubular portion 13 make it possible to assemble the components of the seal construction. Moreover, since part of the needed flexibility is supplied by the tubular portion 13, the seal'ring 14 can be stiffer than is the case when the tubular portion 14 is completely rigid. The greater stiffness of the seal the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING ring 14 enhances the reliability of the seal construction and increases the pressure range over which the seal is proof against leakage.

, A further point to be noted is that the contact regions 17 and 15 must, at least in part, lie opposite each other in order to balance the opposing forces exerted by the case body and the tubular portion of the glass annulus In the embodiment shown in FIG. 2, the flexibility of the tubular portion 13 is increased by means of a groove 18 therein. The tubular portion 13 has a bevel l9 and the seal ring has a corresponding bevel 20, these bevels acting as guides in the assembly of the seal rin 14 to the tubular portion 13.

The embodiment-of FIG. 3 is provided with shoulders 21 and 22 in the case body 16 for holding the seal ring I4 against axial thrust.

In the embodiment shown in FIG. 4, the surface 17 of the case body 16 terminates in a ridge 24, as a result of the fact that angle is less than 90. A surface 25 of the case body 16 is cut at an angle so that it constitutes a bevel, and the seal ring 14 is provided with a second bevel 26 to facilitate assembling of the seal ring to the case body.

In designing the seal ring, it is necessary that the sizes and angles of the bevels be carefully selected. If the bevels are too short, or the angles which the bevels make with the axial surfaces are too blunt, assembly will be difficult. Conversely, if the bevels are too long or if the angles between the bevel surfaces and the axial surfaces are too acute, the contact surfaces between the seal ring and the other components will be too short and the reliability of the seal will be degraded. It has been found that suitable angles for each particular combination of components can readily be determined experimentally.

The embodiment of FIG. has an L-shaped seal ring 14 having a radial arm 27. The thickness of the radial ram 27 in an axial direction is greater than the height a of the bevel 26 in the seal ring 14. This is necessary in order to provide adequate contact surface between the seal ring and the case body at the surface 17. The tubular portion 13 seats against the seal ring 14 at surfaces 28 and 15. The tightness of the seal can be further improved by the use of adhesive or cement on the surfaces between the tubular portion of the glass annulus and the seal ring.

Referring to the embodiment of FIG. 6, the peripheral surface 17 of the case body 14 and the peripheral surface of the tubular portion 13 are frustocones with approximately equal cone angles. In this embodiment, the resistance of the assembly to separation of the components is increased both by the undercutand the fact that the seal ring is L-shaped.

The L-shape for the seal ring is again shown in FIG. 7 where surfaces 17 and 15 are provided with notches 29 and 30 respectively for holding the seal ring against accidental removal.

An L-shaped seal ring 14 is again shown in FIG. 8, but in this case the radial arm 27 extends in an outward direction. Here the radial arm seats against a shoulder 31 of the case body 16. The usual bevelled guide surfaces 19 and are also provided.

In all of the previous embodiments, the outer diameter of the tubular glass portion 13 of the glass annulus 12 has been smaller than the diameter 17 of the inner periphery of the case body 16. The result, as is obvious, is that the glass cylinder has been internal to the case body, so that in the assembled construction the radial force on the glass cylinder has been inward. This places the glass cylinder in compression, an important consideration, because glass is strong 'in compression. Nevertheless, there are situations in which it is desirable that the glass member be exterior to the case body. Such an embodiment is shown in FIG. 9 where the glass annulus 12 and its tubular section 13 are exterior to the seal ring 14 which in turn is exterior to the case body 16. Here again, an L-shaped seal ring is shown although an essentially I-shaped seal ring could have been used as inthe embodiments of FIGS. 1 through 4.

In general, an L-shaped seal ring, where the tubular portion of the glass annulus seats on the radial arm of the seal ring, has the advantage that contact between the glass member and the case body is prevented. Where the watch is to be subjected to high pressure as in the case of deep sea diving, the axial force of the water pressure might cause fracture in the region of contact between the glass and the case body.

With respect to the tightness of the seal between the seal ring and the case body, it is desirably that the surface of the case body making contact with the seal ring in the finished assembly be highly polished. Further to the aim of providing maximum tightness against leakage, adhesive or cement may be used at .either or both of the pairs of contact surfaces.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above article without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. In a waterproof watch, an improved waterproof seal construction, comprising a glass water crystal having a flexible tubular portion formed with an annular periphery, an annular seal ring of flexible nonelastomeric material selected from the group including plastic and soft metal engaging said periphery of said tubular portion in an interference fit and a casebody having an annular periphery engaging said seal ring in an interference fit, said seal with said interference fits being assemblable by reason of the combined flexibilities of said seal ring and said tubular portion.

2. Waterproof seal construction as defined in claim 1, wherein said seal ring is essentially cylindrical in cross-section.

3. Waterproof seal construction as defined in claim 1, wherein said tubular portion, said seal ring and said case-body have comers which engage in pairs as said seal construction is assembled and at least one pair of said corners is beveled to facilitate assembly of said seal construction.

4. Waterproof seal construction as defined in claim 1, wherein cement is incorporated at said engaging surfaces to improve the reliability and tightness of saidseal construction.

5. Waterproof seal construction as defined in claim 1, wherein said case-body periphery is polished to improve the reliability and tightness of said seal construction.

6. Waterproof seal construction as defined in claim 1, wherein said tubular portion is interior to said annular periphery of said case-body.

7. Waterproof seal construction as defined in claim 1, wherein said tubular portion is exterior to said annular periphery of said case-body.

8. Waterproof seal construction as defined in claim 1, wherein said seal ring is L-shaped in cross-section, one of the arms extending radially from said seal ring.

9. Waterproof seal construction as defined in claim 8, wherein said tubular portion is seated on said radiallyextending arm. 

1. In a watErproof watch, an improved waterproof seal construction, comprising a glass water crystal having a flexible tubular portion formed with an annular periphery, an annular seal ring of flexible nonelastomeric material selected from the group including plastic and soft metal engaging said periphery of said tubular portion in an interference fit and a case-body having an annular periphery engaging said seal ring in an interference fit, said seal with said interference fits being assemblable by reason of the combined flexibilities of said seal ring and said tubular portion.
 2. Waterproof seal construction as defined in claim 1, wherein said seal ring is essentially cylindrical in cross-section.
 3. Waterproof seal construction as defined in claim 1, wherein said tubular portion, said seal ring and said case-body have corners which engage in pairs as said seal construction is assembled and at least one pair of said corners is beveled to facilitate assembly of said seal construction.
 4. Waterproof seal construction as defined in claim 1, wherein cement is incorporated at said engaging surfaces to improve the reliability and tightness of said seal construction.
 5. Waterproof seal construction as defined in claim 1, wherein said case-body periphery is polished to improve the reliability and tightness of said seal construction.
 6. Waterproof seal construction as defined in claim 1, wherein said tubular portion is interior to said annular periphery of said case-body.
 7. Waterproof seal construction as defined in claim 1, wherein said tubular portion is exterior to said annular periphery of said case-body.
 8. Waterproof seal construction as defined in claim 1, wherein said seal ring is L-shaped in cross-section, one of the arms extending radially from said seal ring.
 9. Waterproof seal construction as defined in claim 8, wherein said tubular portion is seated on said radiallyextending arm. 